Determining the Slip Rate and Earthquake Recurrence Interval on the Tip of a Foreberg in the Gobi-Altai, Mongolia

2021 ◽  
Author(s):  
C.H. Lee ◽  
Y.B. Seong ◽  
J.-S. Oh
Keyword(s):  
Surface Deformation ◽  
Slip Rate ◽  
Alluvial Fan ◽  
Recurrence Interval ◽  
Luminescence Dating ◽  
High Mountain ◽  
Earthquake Recurrence ◽  
Mountain Ranges ◽  
Earthquake Recurrence Interval ◽  
Exposure Ages

Abstract ––The Gobi-Altai, Mongolia, includes high mountain ranges that have accommodated the compressional stresses derived from the collision between the Eurasian and Indian Plates. The Gurvan Bogd, which is one of the main mountain ranges in the Gobi-Altai, is a restraining bend along the Bogd sinistral fault. Although surface ruptures did not form near the Artz Bogd during the Mw = 8.1 Gobi-Altai earthquake of 1957, it is still active, as evidenced by a growing topography (i.e., forebergs). Six foreberg ridges have formed in the foreland of the Artz Bogd, which are considered to be the result of surface deformation of alluvial fans due to thrusting. One stream has cut down to expose a foreberg tip, providing the opportunity to explore the slip evolution of the region. Here we map a growing fault structure related to blind thrusting. We identify five faulting events from an analysis of the outcrop and apply optically stimulated luminescence dating to the faulted sedimentary layers, yielding an average slip rate of 0.045 ± 0.007 m/kyr and an earthquake recurrence interval of 5.8 ± 0.5 kyr over the last ~32 kyr. Furthermore, the long-term (~600 kyr) uplift rate of the foreberg is 0.067 ± 0.007 m/kyr, as deduced by dividing the vertical displacement of the alluvial fan surface by the 10Be surface exposure ages of boulders on the fan. The discrepancy (20–30%) between these two deformation rates may be due to the different timescales they cover and an along-strike gradient in slip rate.

scholarly journals Paleo-earthquake Evidence and Earthquake Recurrence for Düzce Fault, Turkey

2021 ◽  
Author(s):  
Tolga Komut ◽  
Ersin Karabudak
Keyword(s):  
Probability Distribution ◽  
Probability Distributions ◽  
Slip Rate ◽  
Recurrence Interval ◽  
Historical Earthquake ◽  
Earthquake Recurrence ◽  
Probability Curve ◽  
Recurrence Model ◽  
Sequential Event ◽  
Earthquake Recurrence Interval

Abstract Paleoseismological trenching was performed along the Düzce fault providing some preliminary insight about its seismogenic behavior. Dating was based on radiocarbon analysis of peat samples collected from the trenches and suggested seven earthquakes have occurred since 1740 BC. Integrating date constraints of events exposed in the trenches suggests a periodical earthquake recurrence model. According to a linear sequential event serial that has minimum misfit determined by considering the probability curve limits of the sample dates, the earthquake recurrence interval is between 384 and 460 years (or possibly between AD 394 and 400). A probability curve was also calculated for the date of the last earthquake (1999 Düzce earthquake) considering the probability distributions of sample dates based on the same event serial. This probability-distribution-based method, similarly, predicted that the 1999 Düzce earthquake occurred between 1933–2005 (± 36 years) with a 68 % probability. After this verification. Using this method, it was estimated that the next earthquake along the Düzce fault has a 68 % probability of occurring between 2328–2392. According to this calculation, the earthquake recurrence interval is about 391 ± 34 years with a 68 % probability and the AD 967 historical earthquake likely ruptured the Düzce fault. Assuming an average slip of 350 cm (the average slip of the 1999 earthquake), the slip rate was estimated to be between 8.7–11.2 mm/a.

Bounds on the Average Recurrence Interval of Major Earthquakes Along the Haiyuan Fault In North-Central China

1988 ◽  
Vol 59 (3) ◽  
pp. 81-89 ◽  
Author(s):  
Zhang Peizhen ◽  
Peter Molnar ◽  
Zhang Weigi ◽  
Deng Qidong ◽  
Wang Yipeng ◽  
...  
Keyword(s):  
Slip Rate ◽  
Recurrence Interval ◽  
Central China ◽  
Great Earthquake ◽  
Average Amount ◽  
Earthquake Recurrence ◽  
Surface Rupture ◽  
North Central ◽  
Recurrence Intervals ◽  
Historic Record

Abstract Evidence of surface rupture has been found in trenches near Caiyuan and Shaomayin along the Haiyuan fault, where a great earthquake occurred in 1920. In addition to the 1920 earthquake, faulting occurred at least once between 2590 ± 190 years and 1525 ± 170 years B.P. in Caiyuan, and there probably was another event since 1525 ± 170 years B.P. The formation and later tilting of fault-related, scarp-derived colluvial wedges in the Shaomayin trench appear to record the occurrence of two pre-1920 events in the last 2200–3700 years, but there could have been three or more events. The average recurrence interval for great earthquakes along the Haiyuan fault probably exceeds 700 years, for the 1920 Haiyuan earthquake is the only major event to have been reported in this area in as many years of recorded history. Using a Holocene slip rate along this fault of 8 ± 2 mm/yr, and 8 m as the average amount of offset associated with past great events that have been determined by our previous studies, the resultant earthquake recurrence intervals would be from 800 to 1400 years. The results from our trenches and the historic record are consistent with this range.

Effects of strong seismic shaking in lake sediments, and earthquake recurrence interval, Témiscaming, Quebec

1991 ◽  
Vol 28 (9) ◽  
pp. 1349-1352 ◽  
Author(s):  
Ronald Doig
Keyword(s):  
Relative Frequency ◽  
Sediment Cores ◽  
Recurrence Interval ◽  
Small Lakes ◽  
Earthquake Recurrence ◽  
Uppermost Layer ◽  
Earthquake Recurrence Interval ◽  
A Minor ◽  
Epicentral Region ◽  
Silt Layer

The magnitude 6.3 Timiskaming earthquake of 1935 resulted in discoloration in small lakes in the epicentral region. Sonar profiles for Lac Tee have shown that organic-rich gyttja has been removed from the sides and redeposited in the deep parts of the lake. Lake sediment cores from deep basins contain a 2–3 cm uppermost layer, which is interpreted as the normal accumulation of sediment since 1935. This is followed by a 20 cm chaotic zone of black gyttja mixed with partly tabular fragments of a previously formed silt layer, underlain by a dense 1–2 cm thick silt horizon. The latter is interpreted as having formed by rapid settling of the denser silicate portion of the resuspended sediment. This 20 cm zone is insufficient to account for the abnormal thickness of gyttja in the basins, so events of this kind would have had to have occurred repeatedly since deglaciation. The only major prehistoric event revealed by these ~100 cm cores is at a depth equivalent to about 1500 years ago, based on the amount of sediment deposited since 1935. A minor silting event occurred about 400 years ago. On this basis, the recurrence interval of magnitude 6 or greater earthquakes is longer at Témiscaming than at Charlevoix, Quebec (75 years historically), consistent with the present relative frequency of small earthquakes in these two regions.

Functionning of the Katari-Lago Menor Basin aquifer, Lake Titicaca-Bolivia, inferred from geophysical, hydrogeological and geochemical data

2020 ◽  
Author(s):  
Céline Duwig ◽  
Gabriela Flores ◽  
Marc Descloitres ◽  
Yvan Rossier ◽  
Lorenzo Spadini ◽  
...  
Keyword(s):  
Groundwater Resources ◽  
Alluvial Fan ◽  
Geochemical Data ◽  
High Mountain ◽  
Anthropogenic Contamination ◽  
Lake Titicaca ◽  
Mountain Ranges ◽  
Eastern Cordillera ◽  
Consistent Picture ◽  
Insight Into

<p>The population of the semi-arid Bolivian Northern Altiplano depends greatly on groundwater resources, surface water being intermittent and often contaminated by human activities. The aim of this study is to provide a first insight into the hydrogeological structure and groundwater dynamics of the Katari-Lago Menor Basin aquifer located between the Eastern Cordillera and Lake Titicaca, Bolivia. Resistivity profiles combined with geology, borehole lithology, topography as well as additional groundwater level and geochemical measurements, were helpful in resolving the spatial limits of the aquifer, the vertical and lateral continuity of the Quaternary porous geologic media, the shape and position of the bottom of the aquifer (depth to the bedrock, i.e. Tertiary or Devonian Formations), and revealed a general overview of the natural dynamic behaviour of the aquifer at the scale of the Katari and Lago Menor Basin. The quaternary sediments are hydraulically connected and behave as a single regional basin-aquifer. The main groundwater flow system starts in the upper Piedmont (high mountain ranges of the Eastern Cordillera) and follows the topographic Piedmont gradient (NE to SW). Most groundwater recharge results from the infiltration of precipitation and runoff on the high mountain ranges. Indeed, groundwater circulating in the upper and lower Piedmont layers present primarily  facies. In the regions of the lower Piedmont urbanized areas, groundwater presenting  facies, show a noticeable enrichment of sulphate and chloride relating mainly anthropogenic contamination (mining and urban nature). A large portion of the aquifer presents an unconfined behaviour whereas it remains confined below the Ulloma Formation. The thickness of the unconfined portion varies from 50 to 150 meters and that of the confined from 100 to 150 meters. Values of hydraulic conductivity for the unconfined portion range from 1.1×10<sup>-4</sup> m s<sup>-1</sup> (alluvial fan deposit), 2.5×10<sup>-6 </sup>m s<sup>-1</sup> (fluvioglacial deposits,) to 5.9×10<sup>-8 </sup>m s<sup>-1</sup> (glacial deposits), while for the confined part transmissivity values range around 6.0×10<sup>-6</sup>  m<sup>2</sup> s<sup>-1</sup> (paleo-lacustrine deposits).</p><p> This multidisciplinary approach proved to be an appropriate method to derive a consistent picture of the hydrogeological functioning of the Katari-Lago Menor Basin aquifer.</p>

New constraints on Quaternary slip partitioning near the eastern termination of the Altyn Tagh Fault 

2021 ◽  
Author(s):  
Nimrod Wieler ◽  
Amit Mushkin ◽  
Eitan Shelef ◽  
Huiping Zhang ◽  
Amir Sagy ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Quaternary ◽  
Slip Rate ◽  
Alluvial Fan ◽  
Luminescence Dating ◽  
The Tibetan Plateau ◽  
Altyn Tagh Fault ◽  
Slip Rates ◽  
Altyn Tagh ◽  
Slip Partitioning

<p>Slip partitioning along the northern boundary of the Tibetan Plateau is essential for understanding regional deformation and the seismic potential of the different faults that accommodate it. Within this framework the Altyn Tagh Fault (ATF) is commonly viewed as the primary structure that separates the Tibetan Plateau from the stable Gobi-Alashan block to the north. Late Quaternary sinistral slip rates of 8-12 mm/yr across the central ATF between 86° and 93°E decrease eastwards to zero as the fault approaches its mid-continental termination at ~97°E. To better understand how late Quaternary slip is partitioned along the ATF’s eastern termination we obtained new slip-rate measurements  for the ~200-km-long left-lateral ENE striking Sanweishan Fault (SSF) located ~60 km north of the ATF between 94°-96°E near the town of Dunhuang.</p><p>Multiple sinistral offsets ranging up to 600 m were identified by linking the clast assemblage of offset alluvial fan remnants with their provenance upstream of the fault.  Luminescence dating revealed depositional ages ranging from 100 - 200 ka for the offset features and time-invariant minimum sinistral slip of 2.5±1 mm/yr during the last ~200 ka, which is approximately an order of magnitude higher than previously reported slip-rates for the SSF. Our results indicate that the SSF and the eastern segment of the ATF accommodate comparable magnitudes of late Quaternary slip. Considering this substantial transfer of lateral slip as far as 60 km north of the eastern ATF we propose that the SSF may represent juvenile northeastward expansion of the Tibetan Plateau into previously stable parts of the Gobi-Alashan block.</p>

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